A traffic signal is a traffic device used to control traffic at intersections by notifying drivers how they may proceed through intersections. Generally, traffic signals employ red, green and yellow light indicators to notify the drivers that if they may proceed through the intersection without stopping or if they must come to a complete stop and wait for a traffic signal to change to “Green” and intersection cross traffic to clear before proceeding. Generally, the traffic signal is not intended for use as a traffic calming device; it is intended to be installed mainly for safety and to assign right-of way for a certain direction. Traffic signals are commonly deployed as control and safety measures in areas with moderate to high levels of traffic in all directions. Traffic signals are usually erected on all intersecting roads, resulting in three-way or four-way traffic signals. A driver is supposed to observe traffic signal status and either proceed through the intersection with a green light, transition or begin to brake for a yellow light or stop at the intersection threshold with a Red Light and wait for a Green Light and clear intersection to proceed.
Presently, Autonomous Vehicles or vehicles that drive themselves are being tested and are in limited production. In the future, these autonomous vehicles will take over our highways. Advanced Sensors, Artificial Intelligence, Neural Networks, Deep Learning and Advanced Communications Links make all this possible. Vehicles are being provided with the latest computer and sensor technology that allows them to drive themselves. The currently available traffic signals are not designed for upcoming autonomous vehicles or self-driven vehicles. As in self-driven vehicles, the vehicle is not driven by humans, these vehicles cannot rely on the human judgment to follow traffic rules at traffic signals. To make a self-driven vehicle intelligent enough to deal with traffic signals will add significant complexity to self-driven vehicles, requiring complex hardware and software support. Further, the chances of an accident may increase, as each vehicle may behave differently based on the hardware and software employed within the vehicle.
The Federal Highway Administration reports approximately 2.5 Million intersection accidents every year. Intersection accidents represent 40% of all accidents nationally are led only by rear end collisions. Most intersection accidents involve left turns. Fifty percent of serious accidents happen in intersections and approximately 20% of fatal accidents occur there. Red Light runners are responsible for approximately 165,000 accidents that occur annually. As autonomous vehicles are introduced into the highway system and are becoming increasingly popular, a decrease in accidents at intersections is anticipated as driver and driverless vehicles navigate the highways. It may take 30-50 years or more for autonomous vehicles to completely take over our highways and until that time, driver and driverless vehicles will share our streets and highways, presenting new challenges for traffic control and safety at intersections.